From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-xfs@vger.kernel.org
Subject: Re: [PATCH] xfs: only reclaim unwritten COW extents periodically
Date: Mon, 6 Mar 2017 16:17:02 -0800 [thread overview]
Message-ID: <20170307001702.GH5280@birch.djwong.org> (raw)
In-Reply-To: <20170228052651.GD5297@birch.djwong.org>
On Mon, Feb 27, 2017 at 09:26:51PM -0800, Darrick J. Wong wrote:
> On Mon, Feb 27, 2017 at 04:49:10PM -0800, Christoph Hellwig wrote:
> > We only want to reclaim preallocations from our periodic work item.
> > Currenrly this is archived by looking for a diry inode, but that check
> > is rather fragile. Instead add flags to the xfs_reflink_cancel_cow_* so
> > that the caller can ask for just cancelling unwritten extents in the COw
> > fork.
> >
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > ---
> > fs/xfs/xfs_aops.c | 2 +-
> > fs/xfs/xfs_icache.c | 2 +-
> > fs/xfs/xfs_inode.c | 2 +-
> > fs/xfs/xfs_reflink.c | 14 +++++++++-----
> > fs/xfs/xfs_reflink.h | 5 +++--
> > fs/xfs/xfs_super.c | 2 +-
> > 6 files changed, 16 insertions(+), 11 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
> > index b480647e00e7..290c0fb306e7 100644
> > --- a/fs/xfs/xfs_aops.c
> > +++ b/fs/xfs/xfs_aops.c
> > @@ -293,7 +293,7 @@ xfs_end_io(
> > goto done;
> > if (ioend->io_bio->bi_error) {
> > error = xfs_reflink_cancel_cow_range(ip,
> > - ioend->io_offset, ioend->io_size);
> > + ioend->io_offset, ioend->io_size, 0);
> > goto done;
> > }
> > error = xfs_reflink_end_cow(ip, ioend->io_offset,
> > diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> > index 7234b9748c36..1f7d158266c1 100644
> > --- a/fs/xfs/xfs_icache.c
> > +++ b/fs/xfs/xfs_icache.c
> > @@ -1608,7 +1608,7 @@ xfs_inode_free_cowblocks(
> > xfs_ilock(ip, XFS_IOLOCK_EXCL);
> > xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
> >
> > - ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
> > + ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, XFS_CC_UNWRITTEN);
>
> Ok, so the periodic work item leaves real cow extents alone now, which
> is good since real extents now represent pending cow operations. Good.
>
> > xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
> > xfs_iunlock(ip, XFS_IOLOCK_EXCL);
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> > index edfa6a55b064..164e74a511b1 100644
> > --- a/fs/xfs/xfs_inode.c
> > +++ b/fs/xfs/xfs_inode.c
> > @@ -1615,7 +1615,7 @@ xfs_itruncate_extents(
> >
> > /* Remove all pending CoW reservations. */
> > error = xfs_reflink_cancel_cow_blocks(ip, &tp, first_unmap_block,
> > - last_block);
> > + last_block, 0);
> > if (error)
> > goto out;
> >
> > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> > index 08ca9f81b087..83605af3b135 100644
> > --- a/fs/xfs/xfs_reflink.c
> > +++ b/fs/xfs/xfs_reflink.c
> > @@ -551,7 +551,8 @@ xfs_reflink_cancel_cow_blocks(
> > struct xfs_inode *ip,
> > struct xfs_trans **tpp,
> > xfs_fileoff_t offset_fsb,
> > - xfs_fileoff_t end_fsb)
> > + xfs_fileoff_t end_fsb,
> > + unsigned flags)
> > {
> > struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
> > struct xfs_bmbt_irec got, del;
> > @@ -575,7 +576,8 @@ xfs_reflink_cancel_cow_blocks(
> > &idx, &got, &del);
> > if (error)
> > break;
> > - } else {
> > + } else if (del.br_state == XFS_EXT_UNWRITTEN ||
> > + !(flags & XFS_CC_UNWRITTEN)) {
> > xfs_trans_ijoin(*tpp, ip, 0);
> > xfs_defer_init(&dfops, &firstfsb);
> >
> > @@ -623,7 +625,8 @@ int
> > xfs_reflink_cancel_cow_range(
> > struct xfs_inode *ip,
> > xfs_off_t offset,
> > - xfs_off_t count)
> > + xfs_off_t count,
> > + unsigned flags)
> > {
> > struct xfs_trans *tp;
> > xfs_fileoff_t offset_fsb;
> > @@ -649,7 +652,8 @@ xfs_reflink_cancel_cow_range(
> > xfs_trans_ijoin(tp, ip, 0);
> >
> > /* Scrape out the old CoW reservations */
> > - error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb);
> > + error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb,
> > + flags);
> > if (error)
> > goto out_cancel;
> >
> > @@ -1437,7 +1441,7 @@ xfs_reflink_clear_inode_flag(
> > * We didn't find any shared blocks so turn off the reflink flag.
> > * First, get rid of any leftover CoW mappings.
> > */
> > - error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF);
> > + error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF, 0);
> > if (error)
> > return error;
> >
> > diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
> > index 33ac9b8db683..9416279b3c89 100644
> > --- a/fs/xfs/xfs_reflink.h
> > +++ b/fs/xfs/xfs_reflink.h
> > @@ -37,11 +37,12 @@ extern bool xfs_reflink_find_cow_mapping(struct xfs_inode *ip, xfs_off_t offset,
> > extern void xfs_reflink_trim_irec_to_next_cow(struct xfs_inode *ip,
> > xfs_fileoff_t offset_fsb, struct xfs_bmbt_irec *imap);
> >
> > +#define XFS_CC_UNWRITTEN 0x01
>
> Could we have a comment here about what CC_UNWRITTEN means?
>
> I /think/ it means "don't remove real extents", since when it's specified
> delalloc reservations still get removed by _reflink_cancel_cow_*, correct?
>
> Somewhere we ought to record the fact that flags == 0 removes everything.
It's been a week; ping? (Or: did anyone receive this reply at all?)
--D
>
> --D
>
> > extern int xfs_reflink_cancel_cow_blocks(struct xfs_inode *ip,
> > struct xfs_trans **tpp, xfs_fileoff_t offset_fsb,
> > - xfs_fileoff_t end_fsb);
> > + xfs_fileoff_t end_fsb, unsigned flags);
> > extern int xfs_reflink_cancel_cow_range(struct xfs_inode *ip, xfs_off_t offset,
> > - xfs_off_t count);
> > + xfs_off_t count, unsigned flags);
> > extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset,
> > xfs_off_t count);
> > extern int xfs_reflink_recover_cow(struct xfs_mount *mp);
> > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> > index 890862f2447c..9136854030d5 100644
> > --- a/fs/xfs/xfs_super.c
> > +++ b/fs/xfs/xfs_super.c
> > @@ -953,7 +953,7 @@ xfs_fs_destroy_inode(
> > XFS_STATS_INC(ip->i_mount, vn_remove);
> >
> > if (xfs_is_reflink_inode(ip)) {
> > - error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF);
> > + error = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, 0);
> > if (error && !XFS_FORCED_SHUTDOWN(ip->i_mount))
> > xfs_warn(ip->i_mount,
> > "Error %d while evicting CoW blocks for inode %llu.",
> > --
> > 2.11.0
> >
> > --
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> --
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next prev parent reply other threads:[~2017-03-07 7:24 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-28 0:49 [PATCH] xfs: only reclaim unwritten COW extents periodically Christoph Hellwig
2017-02-28 5:26 ` Darrick J. Wong
2017-03-07 0:17 ` Darrick J. Wong [this message]
2017-03-07 5:00 ` Christoph Hellwig
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